1. Field of the Invention
This invention relates to tie rod ends and, in particular, to removal of lubricants from tie rod ends.
2. Disclosure of the Related Art
Tie rod ends form part of the steering linkage in a vehicle and are coupled to steering knuckles disposed at either end of a steer axle to enable the vehicle operator to steer wheels supported on the knuckles. A conventional tie rod end includes a socket member and a ball stud member, the ball stud member being disposed in the socket member. Lubricants are used to reduce friction and heat created by contact between the socket member and ball stud member. As the lubricants are exposed to such stresses, their composition begins to break down and the lubricants need to be removed and replaced. One conventional tie rod end uses purge holes in a boot seal surrounding the ball stud member to allow the removal of used lubricant. Another conventional tie rod end uses a valve with a flap in the boot seal to allow used lubricant to be purged from the tie rod end.
Conventional tie rod ends have several disadvantages. For example, the use of purge holes in a boot seal allows outside contaminants to enter the chamber defined in the socket member in which the ball stud member is disposed-particularly when the vehicle is in motion (whether such motion occurs during vehicle travel or when the vehicle is at rest and, for example, is being loaded or unloaded). The boot seal operates like a vacuum and absorbs outside contaminants. The use of a valve with a flap in the boot seal reduces the amount of contaminants entering the chamber, but increases the cost of the boot seal. Further the integrity of the valve flap can be compromised.
There is thus a need for a tie rod end that will minimize or eliminate one or more of the above-mentioned deficiencies.
The present invention provides a tie rod end for use with tie rods and steering assemblies.
A tie rod end in accordance with one embodiment of the present invention includes a socket member that defines a first bore at one end of the socket member and a second bore in communication with the first bore. The first and second bores may be disposed about axes perpendicular to each other. The tie rod end also includes a ball stud member, which includes a ball portion disposed within the first bore and a stud portion extending from the first bore. Finally, the tie rod end also includes a purgative zerk disposed in the second bore.
A tie rod end in accordance with a second embodiment of the invention includes a socket member defining a first bore proximate one end and a ball stud member including a ball portion disposed within the first bore and a stud extending from the first bore. The tie rod end also includes a plug that closes one end of the first bore in the socket member. Finally, the tie rod end includes a purgative zerk disposed in the plug.
A tie rod end in accordance with the present invention represents a significant improvement as compared to conventional tie rod ends. In particular, the use of a purgative zerk in either the socket or plug reduces the amount of outside contaminants that enter the tie rod end as compared to conventional tie rod ends. The use of a zerk in the socket or plug allows the use of a purgeless boot seal, which contains no holes and creates a hermetic seal.